Control surface cover



y4,1948 Gasma- 2,441,087'

CONTROL SURFACE COVER Filed May 11, 1945 2 Sheets-Sheet 1' G. D. SYMER 2,441,087

CONTROL SURFACE COVER v Filed May 11, 1945 2 Sheets-Sheet 2 awn Mm Patented May 4, 1948 UNITED STATES PATENT ()FFICE CONTROL SURFACE COVER.

Gerald D. Symer, Greenbelt, Md.

Application May 11, 1945, Serial No. 593,242

This invention relates to a control surface cover, and more particularly to the means for securing and locking in place the fabric covering for airplane surfaces.

One of the important objects of this invention is the production of a simple and efficient means for quickly and securely attaching the cover, skin or fabric sheet to an airplane surface so as to eliminate the tedious stitching or sewing which is usually employed when so attaching the cover in place.

A further object of this invention is the production of a-simple and efficient cover or skin, the leading end trailing edges of which are prepared in advance of attachment so that the cover or skin may be quickly placed in anchored position upon the airplane surface with a minimum amount of effort.

Other objects and advantages of the present invention will appear throughout the following specification and claims.

In the drawings:

Figure 1 is a top plan view partly broken away, of a wing or other portion of an airplane having a control surface;

Figure 2 is a fragmentary sectional perspective view of an airplane wing illustrating one form of my invention;

Figure 3 is an enlarged sectional view taken on line 3--3 of Figure 1;

Figure 4 is an enlarged longitudinal sectional view taken on line 4-4 of Figure 1;

Figure 5 is a transverse sectional view taken on line 5-5 of Figure 1;

Figure 6 is a fragmentary perspective view of one of the anchoring channels;

Figure 7 is a perspective view of a portion of the cover or skin;

Figure 8 is an enlarged transverse sectional view taken on line 88 of Figure 'I;

Figure 9 is a sectional perspective of a portion of the cover or skin illustrating the anchoring strip and manner of attaching the cover or skin to the strip before stitching;

Figure 10 is a fragmentary sectional perspective view of one of the ribs;

Figure 11 is an enlarged top plan view of a portion of the wing illustrating the manner of anchoring the cover or skin in position;

Figure 12 is a fragmentary sectional perspective view of one form of anchoring strip;

7 Figure 13 i a fragmentary perspective view of the trailing edge of the wing or other portion of an airplane;

Figure 14 is a transverse sectional view partly 2 Claims. (01. 244-132) in elevation of an airplane wing illustrating a modified form of fastening means;

Figure 15 is an enlarged transverse sectional view illustrating the anchoring means shown in Figure 14;

Figure 16 is an enlarged transverse sectional view illustrating a further modified means for anchoring the cover to the leading edge of a wing and the like;

Figure '17 is a similar view illustrating a similar means shown in Figure 16 for anchoring the cover to the trailing edge;

Figure 18 is a perspective view partly in section illustrating a further type of anchoring means.

By referring to the drawings by numerals it will be seen that [designates a wing, or other portion of an airplane and the like, wherein a control surface is used. It should be understood at the outset that the present invention is adaptable for use upon any control'surface, such as ailerons, elevators, rudders, and the like, without departing from the spirit of the invention. In the structure illustrated, the leading edge 2 is of the conventional design, and anchoring channels 3 and 3* engage and are secured to the rear margins of the leading edge 2' in any suitable or convenient manner, such for instance as being fixed to the ribs 4. The leading edge 2 is formed of metal or other material common to the trade.

The channel 3 is provided with a straight longitudinal flange 5', which preferably extends under the rear margin of the leading edge 2. The body of the channel 3 is inset from the flange 5 to provide a longitudinally extending straight depression 6. The opposite edge of the channel 3 is provided with a rolled flange I which extends parallel to the flange 5 to provide a rest for the fabric upper and lower covers or skins 8 and 8 and to reduce wear thereon to a minimum. The channel 3 is secured to the upper rear margin of the leading edge 2 whereas the channel 3*, constructed similarly to the channel 3, is secured to'the lower rear margin of the leading edge 2.

In carrying out my invention, I preferably employ a specially designed trailing edge 9 which may be made of metal or other rigid material. This trailing edge may be shaped as to its longitudinal contour to provide the desired design,

such for instance as that shown in-Figure 1. This trailing edge 9 is preferably V-shaped in cross section and having diverging flanges l0 and H extending forwardly thereof, as shown in detail in Figure 13. Each flange l0 and is provided amigos":

to fit the desired surface and a hem, casing or fold i2 is made along the marginal forward and rear edge of the cover to encase and fitsnu'gly around an anchoring strip 13, theextremity L4 of the fabric of the cover 8 being folded-around the strip l3 as shown. The *cover -;8 is p then stitched, as at l5, close to the inner edge of the strip 13, as shown in Figures 7 and 8,'-to firm-ly encase the strip IS. A strip l3 having the transverse c'o'ntou'r ias *showni'n Figure '12, may be used in place of-thestripliif" desired. The hem or casing l Zand'the strip13are-preferably aperture'das at l'fiythrough "which suitable anchoring means such as screws may extend'to hold the strip 'l'3in anchored position in thechannel 3. An anchoring strip 1'3 similar to the strip 13 isscurd withinthe hem l2 and strip l3" are of a proper longitudinal contour to fit into the'chann'ell l'of the upper flange 10 of the trailribs 4, and the strips-l3'and l-3 are anchored or secured in the 'channels dand M respectively, by means of suitable screws or other fastening means H. In all of these cases, a length of fabric seam-tape I8, of the-proper width, "is attached, preferably with *a well-known airplane dope 'to the iouter surfa'ce -of--the-fabric so "as to cover the pointsofconnection of the cover :with the ribs wand-leadingand trailing edges. Thiswillrleave'thewing or-other'structural frame with a substantially uninterruptedfsmooth, flush surface. --The-side edges of the "seam-tape or sealing tape -is-preferablypinked,-as shown. The 'bottomcover'or skinv 8 zis secured in a-manner similar to that-described above.

There are many ways-"in which the cover or :skin may be secured -to the ribs *4 -or within thechannels G and I14. One method isishown Figures 5"and 10. in-thisrform,--theflanges of therib:4 are provided with depressed or'countersunk :nipples "l9 having threaded apertures 20 intowhichthe screws l! are threaded afterpassing throughsthe fabric. Countersunk washers 2 l are preferably fitted'overthe-fabric to receive the heads of "the '-screws, ;and these washers-2 l forcethe' fabric downinto' the nipples 19 to provide=-asecure anchoring means.

The type f fastening illustrated in Figures '4 and '6 "may "be 'used both in '.the *channels and upon' the ribs and the meansforfasten'ing may be" interchangedior substituted onefor the other, that istoi'say, either the form shown in Figure 4 or "Figure '5, without departing from the spirit of the invention. As shown in Figurese; 6 and 13,

a threaded aperture of the speed nu type may be used, if desired, wherein two opposed threaded tongues22ar'e employed for rece'ivingthe threaded end" 'of thescrew Il similar to the screw I M. It is not"desired'to limitt'hepresent inven- 4 covers or skins 23. In this form the leading edge is provided with upper and lower under cut channels 24 and 25 in which the forward edges of the covers 23 are fitted. The edge of each cover 23 is preferably provided with a rod 26 circular in cross-section fitted within a hem 21. The rod and hem extend along the length of the forward edge of the cover. Suitable retaining screws 28 span the channels 24 and 25 in the manner 'showh in l ig'iires 14 ahd 'fdto seal these chanin anchored position.

The rear edges 29 of the covers or skins 23 are locked-"or anchored in channels 3!] of the trailing edge 3! in a manner similar to the channels fi fland fi. A sealing tape 32 may be used to seal these channels in a manner similar to that described above.

Inf i'giires 16 and 17 there is shown a further modified means for anchoring the forward and rear edges 0f the cover 33, which edges carry anchoring strips 34. These strips =34 fit-inchannels carried-by the leading and trailinghdges 36 and 3'1. Suitable anchoring screwy-38 .pass through the cover -33 *and through the metallic retainingstrip 33 -beyond the channels-B5 in the direction -of Ipulljto hold the strips =34 -'in the anchoring-channels=35 Suitable sealing tape *36 covers these 'channels'd 5.

The metallic retaining strip --3-3 has I one "end fitting under the leading edge 36, as shown in Figure 16, while the retaining=screw =38'anchors the opposite edgein'po'sition. A-similar "retaining' strip 533? has-one edge --anchored by the screw or 'screws 338 and the opposite edge fits under the trailing edge' 31-andvpreferably"extends through an -aperture formed-in the rear channel 35 In Figure 18 there is shown a still'fur'ther modified form-of anchoring meansywhereinth'e leading =-edge '37 is provided with upper and lower dove-tail or keystone channels 38' extending along the rear margin of thele'ading-"edge '31. The strailing edge39 is pi'ovi'ded with -similar dove-tail or keystone charmels 40. The forward and rear edges of the cover "or-skin 'areprovided with dove-tail -or keystone strips =42'fitted in suitablehems-"orcasings of i the fabric cover. These strips 42 are slipped in'en'dwise of the channels 38* and and the cover M and strips are then secured in any desired maririer. --A suitable sealing tape 43 is used to cover -all joints, as shown.

It shouldbe Zund'erstcodthat tlie fabric skin or cover is preformed and preshapedfiah'd that the 'anchoringstrip is fixed "withinthe hem or casing along the forward andrear edges' of the skin or 'c'over': prior-*to placing the-skin'or' cover 'in'.-position. Consequently, the skin or cover=may'be rapidly placedin positionwith a-minimumeifort, and the skin or cover is' tlien' fiiiedwithinthe anchoring channel or =chamiels by the securing elements. T

Because *of -tliestruct1ire illustrated and 'described, it will not be nem'e'ssary to rmovethe control-*surface-from'the plane to which it is'attached, since the cover-may be applied while the control surface is"still"-cariied by or attached to the'plan'e.

Having "described -the invention, what is claimed-as new is:

1. A prefabrieateditrailing edge section for 'aircraft structure:comprisingnpp'erand lower forwardly extending ar'id diverging flafiges, each flange having a longitudinally extiifdi ng lnchoring haniil iiar its rearwardeasts for receiving an anchoring strip of a surface cover to anchor a surface cover upon the trailing edge section.

2. An aircraft structure comprising a frame structure having a channel dove-tail in crosssection formed therein, said channel having an open side and one open end, a flexible cover for said frame structure, a rigid member having a dove-tail formation in cross-section fixed at the margin of said cover and fitting longitudinally in said channel for retaining said member in said channel and anchoring the margin of said cover in the channel, said dove-tail formation of said rigid member and channel preventing the removal of the rigid member through the open side of the channel and permitting the removal of the 1 6 REFERENCES CITED The following references are of record in the file of this patent:

5 UNITED STATES PATENTS Number Name Date 1,331,150 Hooper Feb. 17, 1920 1,773,747 Nebhut Aug. 26, 1930 10 1,886,708 Markey Nov. 8, 1932 2,165,459 Seversky July 11, 1939 2,237,275 Koppen Apr. 1, 1941 2,343,505 Gedris Mar. 7, 1944 FOREIGN PATENTS 5 Number Country Date Great Britain Apr. 10, 1919 

